scholarly journals The Kinetics of the Oxidation of Lysine by μ-Peroxo-Bridged Binuclear Cobalt (III) Complex of Succinimide in Aqueous Hydrochloric Acid Medium

2017 ◽  
Vol 2 (1) ◽  
pp. 37-43
Author(s):  
Ahmed Adetoro ◽  
Suleiman O. Idris ◽  
Ameh D. Onu ◽  
Friday G. Okibe
Keyword(s):  
Ionic Strength ◽  
Outer Sphere ◽  
Hydrogen Ions ◽  
First Order ◽  
Hydrochloric Acid Medium ◽  
State Approximation ◽  
Steady State Approximation ◽  
Probable Reaction ◽  
Electron Transfer Processes ◽  
Kinetics Of

AbstractKinetics of oxidation of Lysine (Lys) and mechanisms by μ-peroxo bis[bis(ethylenediamine)succinimidato-dicobalt(III)]dinitratedihydrate; [LCo(μ-O2)CoL](NO3)2.2H2O (L = suc(en)2), hereafter the complex, was investigated at 420 nm wavelength of maximum absorption of the complex under the conditions hydrogen ions concentration = 1.8 × 10−2 mol dm−3, temperature = 24 ± 1 °C, [LCo(μ-O2)CoL2+] = 1.4 × 10−4 mol dm−3 and ionic strength = 0.5 mol dm−3. First order in [LCo(μ-O2)CoL2+] and [Lys] were obtained but inverse first order in [H+]. The proposed overall rate equation is as shown:$$Rate = ({{k_1 } \over {k_2 }} + {{K_1 k_3 } \over {k_4 }}{1 \over {[H^ + ]}})[LCo(\mu O_2 )CoL^{2 + } ][Lys]$$Rate of the reaction decreases when hydrogen ions concentration increase and exhibited converse effect with increase in concentration of ionic strength from 0.1 – 1.3 mol dm−3. Added cations and anions affected the reaction rate and the Michaelis-Menten plot passed through the origin indicating no absence of intermediate complex in the electron transfer processes. Putting all the results obtained together, the most probable reaction mechanism is in favour of outer-sphere and an appropriate rate law is established using steady state approximation.

scholarly journals The Kinetics of the Oxidation of Lysine by μ-Peroxo-Bridged Binuclear Cobalt (III) Complex of Succinimide in Aqueous Hydrochloric Acid Medium

2017 ◽  
Vol 0 (0) ◽  
Author(s):  
A Adetoro ◽  
S.O. Idris ◽  
A.D. Onu ◽  
F.G Okibe
Keyword(s):  
Ionic Strength ◽  
Outer Sphere ◽  
Hydrogen Ions ◽  
First Order ◽  
Hydrochloric Acid Medium ◽  
State Approximation ◽  
Steady State Approximation ◽  
Probable Reaction ◽  
Electron Transfer Processes ◽  
Kinetics Of

Abstract Kinetics of oxidation of Lysine (Lys) and mechanisms by μ-peroxo bis[bis(ethylenediamine)succinimidato-dicobalt(III)]dinitratedihydrate; [LCo(μ-O2)CoL](NO3)2.2H2O (L = suc(en)2), hereafter the complex, was investigated at 420 nm wavelength of maximum absorption of the complex under the conditions hydrogen ions concentration = 1.8 × 10-2 mol dm-3, temperature = 24 ± 1 °C, [LCo(μ-O2)CoL2+] = 1.4 × 10-4 mol dm-3 and ionic strength = 0.5 mol dm-3. First order in [LCo(μ- O2)CoL2+] and [Lys] were obtained but inverse first order in [H+]. The proposed overall rate equation is as shown: Rate of the reaction decreases when hydrogen ions concentration increase and exhibited converse effect with increase in concentration of ionic strength from 0.1 - 1.3 mol dm-3. Added cations and anions affected the reaction rate and the Michaelis-Menten plot passed through the origin indicating no absence of intermediate complex in the electron transfer processes. Putting all the results obtained together, the most probable reaction mechanism is in favour of outer-sphere and an appropriate rate law is established using steady state approximation.

THE KINETICS OF THE FORMATION OF THE MONOSULPHATO COMPLEX OF IRON (III) IN AQUEOUS SOLUTION

1962 ◽  
Vol 40 (9) ◽  
pp. 1836-1845 ◽  
Author(s):  
G. G. Davis ◽  
W. MacF. Smith
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Ionic Strength ◽  
Continuous Flow ◽  
Hydrogen Ions ◽  
Kcal Mole ◽  
Forward Reaction ◽  
First Order ◽  
Kinetics Of Formation ◽  
Kinetics Of

The kinetics of formation of the monosulphato complex of iron (III) has been examined spectrophotometrically using a continuous-flow technique over the range of temperatures 15.6 to 34.5 °C in an aqueous medium of ionic strength 0.5 and a range of concentrations of hydrogen ions 0.05 to 0.30 M. The experimental data may be interpreted on the assumption that the significant reactions are a bimolecular association opposed by a first-order dissociation [Formula: see text] For the forward reaction ΔH≠ is 18.0 kcal mole−1 and ΔS≠ is 19.4 cal mole−1 deg−1.

scholarly journals Kinetics and Mechanism of Redox Reaction of Neutral Red with Nitrite Ion in Aqueous Acidic Medium

2016 ◽  
Vol 67 ◽  
pp. 50-57
Author(s):  
Ismaila Ibrahim ◽  
Sulaiman Ola Idris ◽  
Ameh David Onu
Keyword(s):  
Redox Reaction ◽  
Outer Sphere ◽  
Neutral Red ◽  
Nitrite Ion ◽  
First Order ◽  
Hydrochloric Acid Medium ◽  
Plausible Mechanism ◽  
Kinetics Of ◽  
Sphere Mechanism ◽  
Aqueous Acidic Medium

The kinetics of redox reaction of neutral red, NR+, with nitrite ion, NO2-, was studied in aqueous hydrochloric acid medium under pseudo-first order conditions at 25 ± 1°C, [H+] = 2.0 × 10-3mol dm-3, I = 0.1 mol dm-3(NaCl) and λmax= 525 nm. The reaction was first order with respect to [NR+], [NO2-] and [H+]. The reaction displayed a negative Bronsted-Debye salt effect. There was no evidence of the formation of an intermediate complex of significant stability and free radicals are probably not present in the reaction. The observations above, coupled with the result of Michaelis-Menten plot suggests an outer sphere mechanism for the reaction. The reaction obeys the rate law: -d [NR+]/dt = (a + b [H+])[NR+][NO2-]. A plausible mechanism has been proposed for the reaction.

Kinetics and Mechanism of Hexachloroiridate(IV) Oxidation of Arsenic(III) in Acidic Perchlorate Solutions

1992 ◽  
Vol 57 (7) ◽  
pp. 1451-1458 ◽  
Author(s):  
Refat M. Hassan
Keyword(s):  
Ionic Strength ◽  
Fractional Order ◽  
Activation Parameters ◽  
Order Reaction ◽  
First Order Reaction ◽  
Intermediate Complex ◽  
Constant Ionic Strength ◽  
Kinetics Of Oxidation ◽  
First Order ◽  
Kinetics Of

The kinetics of oxidation of arsenic(III) by hexachloroiridate(IV) at lower acid concentrations and at constant ionic strength of 1.0 mol dm-3 have been investigated spectrophotometrically. A first-order reaction in [IrCl62-] and fractional order with respect to arsenic(III) have been observed. A kinetic evidence for the formation of an intermediate complex between the hydrolyzed arsenic(III) species and the oxidant was presented. The results showed that decreasing the [H+] is accompanied by an appreciable acceleration of the rate of oxidation. The activation parameters have been evaluated and a mechanism consistent with the kinetic results was suggested.

The comparative chemistry of ammine and methylamine complexes of rhodium(III) and cobalt(III)

1977 ◽  
Vol 55 (17) ◽  
pp. 3166-3171 ◽  
Author(s):  
Thomas Wilson Swaddle
Keyword(s):  
Ionic Strength ◽  
Spectral Data ◽  
Electron Donor ◽  
Dissociation Constants ◽  
Base Hydrolysis ◽  
Acid Dissociation ◽  
Rate Coefficients ◽  
Acid Dissociation Constants ◽  
First Order ◽  
Kinetics Of

For the aquation of (CH3NH2)5RhCl2+, the first order rate coefficients are represented by ΔHaq* = 101.9 kJ mol−1 and ΔSaq* = −50.2 JK−1 mol−1 in 0.1 M HClO4, while for base hydrolysis the rate is first order in [(CH3NH2)5RhCl2+] and [OH−] at ionic strength 0.10 M and the rate coefficients (in M−1 s−1) are represented by ΔHOH*> = 108.6 kJ mol−1 and ΔSOH* = 74.1 J K−1 mol−1. Acid dissociation constants are reported for (RNH2)5MOH23+ (R = H or CH3; M = Rh or Co), and these, combined with spectral data, show CH3NH2 to be a poorer electron donor than NH3 in complexes of this type, contrary to expectations. The comparative kinetics of reactions of (RNH2)5MCl2+ support the assignment of an Ia mechanism to aquation when M = Rh or Cr, Id to aquation when M = Co, and Dcb for base hydrolysis in all these cases.

Kinetics of iron(III) hydrolysis and precipitation in aqueous glycine solutions assessed by voltammetry

2009 ◽  
Vol 74 (10) ◽  
pp. 1531-1542 ◽  
Author(s):  
Vlado Cuculić ◽  
Ivanka Pižeta
Keyword(s):  
Ionic Strength ◽  
Complex Formation ◽  
Rate Constants ◽  
Glycine Concentration ◽  
First Order ◽  
Mercury Drop Electrode ◽  
Calculated Rate ◽  
Cathodic Voltammetry ◽  
Kinetics Of ◽  
Voltammetric Measurements

The kinetics of iron(III) hydrolysis and precipitation in aqueous glycine solutions were studied by cathodic voltammetry with a mercury drop electrode. The kinetics was controlled by changing ionic strength (I), pH and glycine concentration. Voltammetric measurements clearly showed formation and dissociation of a soluble Fe(III)–glycine complex, formation of iron(III) hydroxide and its precipitation. The rate constants of iron(III) hydroxide precipitation were assessed. The precipitation is first-order with respect to dissolved inorganic iron(III). The calculated rate constants of iron(III) precipitation varied from 0.18 × 10–5 s–1 (at 0.2 M total glycine, pH 7.30, I = 0.6 mol dm–3) to 2.22 × 10–3 s–1 (at 0.1 M total glycine, pH 7.30, I = 0.2 mol dm–3). At 0.5 M total glycine and I = 0.6 mol dm–3, the iron(III) precipitation was not observed.

Kinetics of aquation of the fluoropentaamminecobalt(III) ion

1970 ◽  
Vol 48 (7) ◽  
pp. 1054-1058 ◽  
Author(s):  
T. W. Swaddle ◽  
W. E. Jones
Keyword(s):  
Ionic Strength ◽  
Rate Coefficient ◽  
Hydrogen Ion ◽  
Fluoride Ion ◽  
Kcal Mole ◽  
First Order ◽  
Order Rate ◽  
Relationship Of ◽  
The Relationship ◽  
Kinetics Of

The kinetics of the hydrogen-ion-independent pathway for the replacement of fluoride in aqueous (NH3)5CoF2+ by H2O have been reinvestigated using a specific fluoride-ion electrode, with due regard for the concomitant autocatalytic loss of the ammine ligands. In perchlorate media of ionic strength 0.1 M, the first-order rate coefficient is 1.22 × 10−6 s−1 at 45°, and the kinetics are represented by ΔH* = 24.4 kcal mole−1 and ΔS* = −9 cal deg−1 mole−1 over the range 35–75° at least. The relationship of these data to those for the aquation of other species of the type ML5Xn+ is discussed.

Kinetics and mechanism of disproportionation and ferricyanide oxidation of the 10-methylacridinium cation in aqueous base

1984 ◽  
Vol 62 (4) ◽  
pp. 729-735 ◽  
Author(s):  
John W. Bunting ◽  
Glenn M. Kauffman
Keyword(s):  
Ionic Strength ◽  
Second Order ◽  
Kinetics And Mechanism ◽  
Oxidation Pathway ◽  
First Order ◽  
Aqueous Base ◽  
Ph Range ◽  
Rate Profile ◽  
Kinetics Of ◽  
Major Oxidation

The kinetics of disproportionation and ferricyanide ion oxidation of the 10-methylacridinium cation have been measured spectrophotometrically over the pH range 9–14 in.20% CH3CN – 80% H2O (v/v) and ionic strength 1.0 at 25 °C. Disproportionation is kinetically second-order in total acridine species. The pH–rate profile is consistent with the rate-determining reaction of one acridinium cation with the pseudobase alkoxide anion derived from a second acridinium cation. Ferricyanide ion oxidation is kinetically first-order in each of ferricyanide ion and total acridine species. The pH–rate profile requires three distinct pathways for the ferricyanide ion oxidation of the 10-methylacridinium cation. For pH < 9.7, rate-determining attack of ferricyanide ion on the neutral pseudobase predominates, while for pH > 12.8 the predominant oxidation pathway involves reaction of ferricyanide ion with the pseudobase alkoxide ion. Between pH 9.7 and 12.8, the major oxidation pathway involves initial disproportionation of the acridinium cation followed by ferricyanide ion oxidation of the 9,10-dihydro-10-methylacridine product. This latter route accounts for a maximum of 69% of the total ferricyanide ion oxidation at pH 11.1.

scholarly journals Kinetics and Mechanism of the Oxidation of Naphthol Green B by Peroxydisulphate Ion in Aqueous Acidic Medium

2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
B. Myek ◽  
S. O. Idris ◽  
J. F. Iyun
Keyword(s):  
Acidic Medium ◽  
Reaction Medium ◽  
Intermediate Complex ◽  
Kinetic Investigation ◽  
Hydrogen Ions ◽  
First Order ◽  
Order Dependence ◽  
Naphthol Green B ◽  
Kinetics Of ◽  
Aqueous Acidic Medium

The kinetics of the oxidation of naphthol green B (NGB3−) by peroxydisulphate ion has been carried out in aqueous acidic medium at λmax of 700 nm, T=23±1°C, and I=0.50 mol dm−3 (NaCl). The reaction shows a first-order dependence on oxidant and reductant concentration, respectively. The stoichiometry of the NGB—S2O82- reaction is 1 : 2. Change in hydrogen ions concentration of the reaction medium has no effect on the rate of the reaction. Added cations and anions decreased the rate of the reaction. The results of spectroscopic and kinetic investigation indicate that no intermediate complex is probably formed in the course of this reaction.

THE NON-ENZYMATIC HYDROLYSIS OF ADENOSINE DIPHOSPHATE

1957 ◽  
Vol 35 (12) ◽  
pp. 1496-1503 ◽  
Author(s):  
K. A. Holbrook ◽  
Ludovic Ouellet
Keyword(s):  
Activation Energy ◽  
Aqueous Solution ◽  
Enzymatic Hydrolysis ◽  
Inorganic Phosphate ◽  
Adenosine Diphosphate ◽  
Hydrogen Ions ◽  
Kcal Mole ◽  
First Order ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of the non-enzymatic hydrolysis of adenosine diphosphate in aqueous solution have been studied at pH 3.5 to 10.5 and temperatures from 80° to 95 °C. The reaction has been followed by measuring colorimetrically the inorganic phosphate liberated according to the over-all reaction[Formula: see text]The reaction has been found to be first order with respect to ADP concentration and to be catalyzed by hydrogen ions. From rate studies at pH 8.0 an activation energy of 24.2 kcal./mole was derived. A mechanism is proposed to account for the observed facts and the mechanism for the hydrolysis of adenosine triphosphate is also discussed.

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